A bighorn ram is hobbled and its eyes are covered while workers fit it with a radio collar. Colorado Parks and Wildlife will track 10 rams from herds concentrated around the Maroon Bells-Snowmass Wilderness to learn their travel patterns. The study could lead to management practices that help stabilize populations.

ASPEN, Colo.—The population of Colorado’s bighorn sheep herds in the Maroon Bells-Snowmass Wilderness has plummeted over the past 15 years and wildlife officials want to know why.

The Colorado Parks and Wildlife Division captured 10 bighorn rams last week and outfitted them with tracking collars.

According to the Aspen Times ( http://tinyurl.com/ba5xo8d), officials are worried because bighorn sheep are dying from respiratory disease possibly caused by bacterial pneumonia. Two of the three herds in the wilderness area have been hit hard. Little is known about a third herd.